The Seattle Mariners announced that they are moving in portions of the outfield wall at Safeco Field for the 2013 season. The changes, which will primarily affect the left field power alley, are the first to the field dimensions since the ballpark opened in 1999.

Executive Vice President and General Manager Jack Zduriencik said, "Our goal was to create an environment that is fair for both hitters and pitchers. Considering the current field dimensions as well as the climate in and around Safeco Field, we feel this will be accomplished with this new layout."